Your situation sounds similar to how mine was--STBXW didn't make much effort for D, and was content to leave everything on autopilot (i.e. me taking care of them). She INSISTED on her weekends, though, and when she had D, D's sleep schedule was always all over the map (as it was when STBXW was still at home). "Her" weekends often involved D spending time at MILs house as well.
Like you, I got tired of it. I ended up ripping STBXW a new a**hole one day, demanding that she be a better mother--if she wasn't going to be a wife anymore than she could damned well do that. It didn't work, of course. I think what finally woke her up was the prospect of our interim parenting arrangement becoming permanent (at which point she claimed that what we'd been doing for over half a year was suddenly a massive problem that "extinguished her rights")
The best advice I got here was "it's not your job to foster their relationship. It IS your job to not damage it." Try to live by that, and just try to do the best you can for your kid to be both mommy AND daddy in her absence.
